Japanese Laid-Open Patent Publication No. 2005-271618 (hereinafter referred to as “JP 2005-271618 A”) discloses an accelerator reaction force control apparatus for use in a hybrid electric automobile. According to JP 2005-271618 A, more specifically, the accelerator reaction force control apparatus has a motor traveling region within which the hybrid electric automobile is driven by a vehicle driving motor 7, and an engine traveling region within which the hybrid electric automobile is driven by an engine 6, and increases a depression reaction force applied to an accelerator pedal 2 when the motor traveling region changes to the engine traveling region (Abstract). Therefore, when the motor 7 switches to the engine 6, a reaction force is applied to the accelerator pedal 2 in order to inform the driver that switching is taking place with the reaction force applied to the accelerator pedal ([0005]).
JP 2005-271618 A also discloses a control process for charging a battery on a hybrid electric automobile by driving the hybrid electric automobile with only the engine 6 if the charged energy level of a battery on the hybrid electric vehicle is not equal to or greater than a predetermined value (step S1: NO of FIG. 4→step S9, [0018], claim 2).